There are two types of roof-mounted known structures for collecting solar energy, one in which a heating medium sealed in a transparent sheet is heated by means of solar energy to make use of the resultant heat; and another, in which a solar energy collection member made of amorphous silicon or crystalline silicon is mounted on the back side of a light-transmitting sheet.
However, when the entire surface of a roof is covered with solar energy collection members, the cost goes up and a large number of solar energy collection members of different dimensions are required to be in combination with each other to correspond to the size of the roof surface. Also, the roof increases in weight, so that rafters and sheathing boards have to bear substantial weight. Since each of these conventional structures is complicated in structure and includes a large number of members, the erection of such conventional roofmounted roof structures is troublesome, and the correction of dimensional errors is troublesome, so that it has been impossible to provide a roof with a sufficient surface for use in collecting solar energy.